Linear Hall effect sensors measure the strength of a magnetic field and output a voltage proportional to that measurement. Based on the degree range and resolution needed, one or more linear Hall sensors can be used to determine the magnet direction. This application report covers angle measurements using no calibration, peak calibration, lookup table calibration, and a hybrid method of both the peak calibrated and lookup table methods.

The two main types of magnetization in permanent magnets are axial and diametric. This terminology makes most sense when talking about discs, cylinders, and ring magnets. Axial magnets have north and south poles that are on the flat surfaces of the magnet. Diametric magnets have north and south poles that are on the rounded edges of the magnet.

Some examples of axially magnetized magnets are the two left magnets in Figure 2-1 and the two left magnets in Figure 2-2.

Some examples of diametrically magnetized magnets are the two right magnets in Figure 2-1 and the two right magnets in Figure 2-2.

Other magnet types are typically referred by shape, such as block and sphere magnets (Figure 2-3 and Figure 2-4), or by unique polarity, for example a multipole ring magnet (Figure 2-5).